Snoverwhelming: Tracking another snow chance

Next Chance of Accumulating Snow: Monday-TuesdayProbability of Accumulating Snow (1" or more): 55%

Though we're catching a short break from any storminess through the weekend, model data suggest we may have another potential snowmaker moving into the region on Monday.

A vigorous disturbance (or clipper) diving south on the polar jet stream will likely pass just to our south. This will place it in a favorable position to produce a period of light to moderate snow over the metro region Monday afternoon and/or night.

There is also some possibility it will interact with the development of an area of low pressure off the coast -- evolving in a similar fashion to yesterday's storm. While current data do not suggest as intense a storm would form, the overall set up and flow pattern in the atmosphere will be similar in some respects. So the potential evolution of this disturbance will need to be watched very carefully over the coming days.

As with any storm more than 48 hours away, accumulation estimates are very uncertain. Here's a preliminary look at accumulation probabilities:

Question for the CWG: what is causing this unusual weather pattern from a scientific perspective? Been living in this area since 1968 and don't recall these types of successive storms and patterns. This may have been debated and discussed on previous threads, so forgive if redundant..

Just want to say "thank you" for all your work and info on this site. I read it religiously and have not been disappointed yet.. and with all the links you set up for us, I have learned quite a bit. Keep up the good work!
Snow? More snow? It is a little scary... weren't we at this point last week at this time?? Thanks guys.

elizamil: Sometimes our weather gets stuck in repetitive patterns. Usually, it's with rain so we slowly forget the sequence of rainy weekends, or the minor episodes of flooding. This year, we have a very active southern jet providing a parade of storms while a block in the northern jet keeps the cold air locked in over the East Coast. The result is a stormy and snowy pattern. In 1996, we also had a sequence of snowstorms, but in that year, most of the snow on the ground melted before the next storm.

On par with elizamil's question, I heard or read somewhere that the increased snow in this region is related to global warming. Specifically, that the release of moisture from the arctic ice caps is resulting in more of these storms forming. Does anyone know anything about this? I realize global "warming" isn't just about the actual rising temperature, but also disturbances in weather patterns that can, in some places, result in colder and snowier weather.

Once again, bdeco, your comment intrigues me. It does seem like there has been some bias in previous storm models and DC has been a bit of a magnet for storms.

But wasn't it the case with this last storm, Snowverkill, that the low was actually predicted by the models to form pretty much exactly where it ended up forming? Then the CWG based their more conservative predictions on the low forming in a position just north enough and in a manner for periods to dry slot the region and have some mixing, where NWS read the models to crush us? The truth ended up being somewhere between the two with the variable being how intense the storm became and how slowly it pulled out of the area.

Am I understanding that correctly and not sure exactly what that tells us from the trends of the models?

As the CWG forecasters say, it's impossible to tell so many days in advance. Then again, after seeing this winter's pattern, if the forecast says "less than 1 inch" now, we'll get a foot of snow on Monday.

@SA-Town
Yes, this is how the forecast started out the last time around, and again there is the possibility of picking up moisture from the coast - but it's still early yet. It remains to be seen whether the accumulation predictions will start creeping up as the new storm approaches!

Just a comment on my last post...I was taking into account predictions by all the forecasters, but I think CWG was more on the mark than most...that's why so many of us follow the blog and appreciate the clear and regularly updated info. provided.

All the latest GFS runs have shown some form of precipitation there, just not that much. What are the chances snow to liquid ratios are high with this storm bringing accumulations up past 1 or 2 inches?

Accuweather is estimating 3.1" for the 2/15. Won't work. We need 4.1" to hit 60" at DCA (unless IAD is willing to loan DCA some of its 75" inches).

The Baltimore total of 79.1" is mindboggling.

Almost as mindboggling: the stupid, careless things people are doing in the aftermath of this storm. Like the idiots who left their dog inside the front of the Glover Park Whole Foods this a.m. The dog bolted out the door and ran up and down Wisconsin Ave. for a while 'til they finally got it on the sidewalk. And yes, there was plenty of traffic!

Seems to me I remember a somewhat similar pattern during the winter of I think 93-94, but it was all ice. Every 3-4 days we got a new mess to contend with. I remember sliding down my driveway after I fell trying to scrape more ice off my car, and grabbing the trailer hitch on the back of my mini-van to keep from sliding all the way into the street and down the hill ...

And I too would like a response to Stat regarding the effects of global warming on our weather patterns ...

With the way the costal jet stream has been huggung the mid-east coast, is there a possibility that the system currently sitting over TX might surprise us and drop some precip on us if it doesn't head out to sea near the Carolinas? I know that the NAM and the GFS are not projecting that right now, but the theory seems to have some basis in recent history.

Would just love to say that for all you natives (and southerners) who spend 8 months outside in the oppressive heat and humidity - life is a Big B!!!! This is the best winter ever since moving from Manhattan over a decade a go - I just wish this was the norm every winter - from Oct. through March. Bring it on - I will never long for the typical DC weather - humid, hot, and horrendous...the air is clean, the freaks are at home and every one is covered up...WINTER IS BEST - SUMMER SUCKS!!!!

Is there any established rule of thumb or relationship between daytime highs and how many inches of snow melts per day?

E.g.

32 - 35 = 1 inch per day

35-40 = 3 inches per day

40 - 45 = 5 inches per day

I know that's really simple. There are lots of other factors such as sunshine and night time freezing. The 10-day forecast showing most daytime highs in the 30s and I'd love to know how much relief that implies we will we get. My dogs want their yard back (I probably have 45 inches back there.)

I have lived here for 27 winters, and I can count on my thumbs the number of clippers that have given us a reasonable amount of snow. The most recent time was this past January, when DCA got 1 inch and Glover Park got 1.5. One other time years ago we got 3 or 4 out of one. In Boston, on the other hand, you could count on one or two per winter, with 5 or 6 inches not that unusual. The reason is that it's rare for them to go south of us down here, which they need to do for us to get any snow, and there's no good moisture source (in Boston they get a little from Long Island-Vineyard-Nantucket Sound).

As for the 1-3" "Most Likely" forecast -- it is easy enough to calculate expected snowfall amounts based on the probability distribution presented in the article (45% less than 1"; 30% 1-4", 15% 4-8"; 10% > 8"). Taking the low end of each snowfall amount group -- i.e., 0, 1, 4, and 8" --yields expected snowfall of 1.7". (0" x .45 + 1" x .30 + 4" x .15 + 8" x .10 = 1.7"). Taking high end of each group (using 12" as upper bound for the high snowfall group) yields expected snowfall of 4.1". Using the midpoint of each group -- i.e., 0.5, 2.5, 6 and 10 -- yields expected snowfall of 2.9". If anything, a "Most Likely" range of 1-3" seems a bit conservative given the probability distribution reported.

I was just out there driving, everything seem under control. They were clearing-up --all the way to the pavement, which is in itself amazing by New York standards, say-- the fourth and ultimate lane on I 395. But I trust your idiotic gang will find a way to make it sound like another apocalyptic event before long.

Arlington County please come plow. NO phone or email response and NO snow clearance... so, how do you expect school administrative employees to report on time as required Friday? We have people shoveling the streets in our neighborhood -- hey County Board where should we send the bill?? -- oops I forgot this is Arlington, I'll pay my taxes and not expect anything in return.
Don Weber
2012 North Upland

Anthropogenic Climate Change (ACC) is likely having some kind of an an effect. The higher average temperature readings all around the globe are showing there is more energy in the atmosphere now than the past ~2k years. So, if you remember in physics; temperature = energy. All the extra energy has to go somewhere. This excess results in more active weather around the globe. However, these storms are too localized for ACC to be the only factor.

These snow storms are actually more the result of a steady, yet moderately strong El Niño season (the warming of the Pacific Ocean, don't ask me why this happens, it just does) which has world-wide effects on local weather patterns for most of the globe. Some places are abnormally hot and moist, while other places can get abnormally cold and dry or any other combo of those things. We just happen to get the colder, wetter part of the deal.